1. Field of the Invention
The present invention generally relates to a sensorless motor apparatus, in particular, to a back electromotive force (EMF) detector of a sensorless motor apparatus.
2. Description of Related Art
In the prior art, in order to achieve the disposition of a sensorless motor apparatus, the deduction of the state of a rotor of the motor is an important subject. It is a common practice to convert a virtual sensing signal of the motor rotor through a back EMF of a motor.
In the prior art, the virtual sensing signal is obtained through an operation performed by using parameters of the motor in combination with multiple electrical and mechanic properties of the motor in operation. In this calculation manner, in addition to a look up table (LUT) of a certain size, some complicated operations are required. In order to deal with such calculation requirements, a high-efficiency processor (for example, a Digital Signal Processor, DSP) is essential. That is to say, the cost for disposing the sensorless motor apparatus is accordingly increased, thus correspondingly lowering the competition of the product.